Brake shoe



May 12, 1925 1,537,911

0. B. WUNSCHOW 1 BRAKE 5110111 Filed Dec. 31, 1925 1 [N VISNTOA (72% Z.l Vzwckozz/ Patented May 12, 1925.

PATENT OFFICE.

OTTO B. WUNSCHQW, OF CHATTANOOGA, TENNESSEE BRAKE SHOE.

Application filed December 31, 1923. Serial No. 683,675.

To all whom it may concern:

Be it known that I, O'rro B. W'uNscrrow, a citizen of the United States,residing at Chattanooga, in the county of Hamilton and State ofTennessee, have invented certain new and useful Improvements in BrakeShoes; and I do hereby declare the follow ing to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

This invention relates to improvements in brake shoes andre-inforcements therefor, and has for its primary object the productionof a shoe of maximum stability which will remain true and hangaccurately relative to the wheel and be effective even when worn down tothe reinforcing means.

With this and further objects in view as will in part hereinafter becomeapparent and in part be stated, the invention coinprises certain novelconstructions, combinations and arrangements of parts as subse quentlyspecified and claimed.

In the accompanying drawings,-

Figure 1 is a view in side elevation of a brake shoe embodying thefeatures of the present invention.

Figure 2 is a top plan view thereof.

Figure3 is a perspective view of the back and key loop detached.

Figure 4 is a transverse section taken approximately midway of thelength of the structure as seen in Figures 1 and 2.

Figure 5 is a fragmentary section through the back and loop detached,the parts being seen on an enlarged scale.

a Figure 6 is a view similar to Figure 5 of a slightly modifiedembodiment.

Figure 7 is afragmentary, inverted plan of the central portion of theback and loop,

part being broken out for showing structure below.

Referring to the drawing by numerals, 1 indicates a wrought plate,preferably of malleable steel, formed with its edges beveled, at 2, 2,for bonding purposes, and also formed with longitudinal slots 3, 3, eachof which is surrounded by beveled edges 4 for increasing theeffectiveness of the bond. Approximately midway of the length of theplate 1, the same is formed with a l0n-' gitudinal slot 5 throughwhic'h'extends a loo 6 of material similar to plate 1, and designed toprovide an accurate key-way for the attaching lug hereinafter mentioned.

The loop 6 is formed of a strip of material bent into U-shapewith thelegs bent outward beneath the plate 1, and the plate 1 is formed withnotches or recesses 7, 7,

openinginto the slot 5 for accommodating the vertical or leg portions ofthe loop 6.

The recesses 7 insure accurate assemblage of the loop within the plate 1in the first instance, and also serve to prevent any edgewise movementof the loop during subsequent operations. The said notches, therefore,in initially locating and subsequently retaining the loop in placeduring casting, prevent distortion or oblique location of the loop 6,which insures an accurate key-way and a consequent true and accuratehanging of the brake shoe.

The plate 1 is formed by any of the well known methods, and the slot 5with therecesses 7 is preferably stamped through the plate 1, orotherwise formed in a quick and inexpensive manner, so that there may attimes appear a slight looseness between the loop 6 and engaged recesses.To avoid any possible dislocation of the loop 6 during the subsequentcasting operation. the underlap'ping, outwardly-turned portions 8, 8, ofthe loop are preferably anchored to the plate 1 after the loop has beenlocated in any ofvarious acceptable ways. as, for example, by the spotwelding indicated at 9 in Figure 5. A rivet or like connectingmember,.'such as seen at 10 in Figure 6, may be employed when preferredin lieu of the spot welding. As the balance of Figure 6 shows astructure identical with Figure 5. the reference numerals above usedand-the foregoing description will apply.-

When the parts have been assembled, as seen in Figure 3, and the loop 6anchored to the plate 1, the plate is inverted'to the position seen inFigure 7, and in this posi-' tion is introduced into a mold which isclosed and the molten iron is then poured in to form the completed brake.shoe 11, as seen in Figures 1, 2 and 4. Thisbrake shoe may be ofvarious sizes, contours and dimensions, but always preferably conformingwith the requirements of the .Master Car Builders Association so as' tofit the standard brake heads. The cast metal, as clearly seen in Figures1,2 and 4,-covers the end portions of platel and effectively bondsthrough the slots 3, overlapping the beveled edges 4 and alsooverlapping the beveled edges 2. The cast metal also fills in the spacebetween the legs of the loop 6 and rises through the slot 5, forming asolid filler above the plane of the adjacent upper surfaces of plate 1,leaving only a key-way 12, and, outside of the loop 6, the cast metalextends above the loop and overlies a part of the cross plate thereof,leaving'only the requisite portion of such plate exposed for effectiveengagement with the brake hanger. Thus the attaching lug 13 is formed ofmaximum stability with the key-way 12 formed with that precision andaccuracy assuring the hanging of the brake shoe in exactly the properrelation to be most effective in engaging the wheel. In structuresheretofore produced, the malleable loops employed have not beenaccurately maintained in place, and an angularly or oblique relation ofthe shoe relative to the wheel has followed, which has been especiallydetrimental to the effective brake action and production of rapid wearand early necessity for discarding such shoes;

Also it has been suggested heretofore that a brake shoe back ofmalleable material be employed with a central slot for the introductionof a hanger loop, which slot should be ofa, length equal to or. greaterthan the length of the core employed for preserving the key-way in theloop during the casting operation. Such an enlarged, central slot in thebacking plate has,- of course, facilitated introduction of the said.core, but in most instances the result was a failure to obtaineffective bonding about the central area of the back and the productionof objectionable sand holes. The present invention provides a slot 5, ofa length less than the actual length of the core to be introduced whichmust .at least be as long or longer than the thickness of the hanger lug13. The slot 5 is, therefore, made, as best seen in Figure 7, slightlylonger than the width of the material of loop 6, so that the core may beintroduced after the plate 1 and loop 6 has been placed in the mold byhavingjthe end of the core inserted between the loop, down through theslot 5 to a point with the lower end beyond the adjacent end of theslot, then lowering the upper end of the core and moving the core ackuntil it res'tscentered. upon the surface of, the cross bar of loop 6.-Thus the slot 5 while of greater length than the width of the materialof-loo 6 is of less length than the thickness oft 0 base of the hangerlug 13, that is, in other words, the slot 5 is of lesslength than thecore to be introduced and insures a conditiomwhen the molding operationisbegumwhich guarantees the production of an efiecting bonding betweenthe cast portions of the shoe and the plate 'as high as ten per cent ofthe production Such loss is total-- incident to such defects. lyeliminated by the present invention. Furthermore, in types of shoesalready in use, the key-ways have been found in instances to be toolarge, allowing the shoes to assume an angular relationship and ride'diagonally on the periphery of the wheel. Such a condition is'impossihlewith a brake shoe embodying the features of the present invention. Inother constructions of brake shoes wherein a backing plate and malleableloop for the hanger lug have been employed, the fitting in of thecoreemployed to produce the key-way'has resulted in the crushing of the sandof the core, leaving floating sand producing defective shoes. Suchconstructions have also been found objectionable, from the presence offins which i have to be clipped and ground after the tumbling operation.The revision for the efl'ective core insertion in t e present inventionboth eliminates danger of floating sand, and enables such precision offit of the parts of the mold as to obviate fins, and assures theconstant and uniform production of shoes which are ready for service asthey come from the tumbler.

What I claim is I L'A brake shoe back comprising a re inforcing platehaving a centrally located slot, and a hanger lug loop extendin throughthe slot, the plate being formed withv recesses opening into the slotfor accommodating the legs of the loop.

2' In a brake shoe, the combination of a re-inforcingplate having alongitudinal slot, a hanger lug" loop extending through the slot, abrake shoe body bonded with the plate-and a brake shoe lug embeddingparts of the -loop,.the slot being of greater length than the width ofthe material of the 100 and of less llejngth'than the width of the lug.3. In a brake shoe, the combination of a re-infor'cing plate having a Vlongitudinal slot, a hanger lug loop extending through the slot, a brakeshoe body bonded .with and a brake shoe lug embedding parts of the loop,the slot being of greater length than the width ofthe material of theloop and of less lengththan'the width of the lug, the material of thebody of the shoe, extending into the loop beyond the said recesses, eachrecess being of a depth plane of the back face of the body and formasgreat as the width of the respective leg ing an integral part of thelug. of the loop for leaving the slot open and 4. A brake shoecomprising a re-inforcfree throughout its length.v

5 ing plate having a centrally located slot extestimony Wher Of I affixmy signature 15 tending longitudinally of the plate, the in p n e of WOWitn ses.

plate being formed at each side of the slot OTTO B. WUNSCHOW. withrecesses extending along the slot and Wit e of a length less than thelength of the slot, LOUISE BERGER,

9 and a loophaving its legs extending through VERA' L. J OHNSON.

